1. Field of the Invention
The present invention relates to a green curable composition, a color filter and a method of producing the same. In particular, the present invention relates to a green curable composition and a color filter for use in a solid-state image sensor and a method of producing the same.
2. Description of the Related Art
Color filters are an essential component for a solid-state image sensor or a liquid display device (LCD). As a composition for forming a color filter, Japanese Patent Application Laid-Open (JP-A) No. 2-199403 describes a negative-type curable composition including a pigment dispersion, an alkali-soluble resin, a photopolymerizable monomer and a photopolymerization initiator. In recent years, there has been demand for color filters used in a solid-state image sensor to enable even higher image quality, and formation of a fine pattern from a composition containing a colorant at high concentration has been required (see, for example, JP-A No. 2006-317893).
Although a dye is employed as a colorant in JP-A No. 2006-317893, pigments are more widely used in view of fastness. In this regard, JP-A No. 2004-46047 describes a color filter containing a pigment as a colorant at high concentration, rather than a dye.
However, the color filter described in JP-A No. 2004-46047 is for use in LCDs, and the pattern size or pattern shape of a colored pattern used in such a color filter is significantly different from that of a color filter for use in a solid-state image sensor. Specifically, color filter used in solid-state image sensors recently have a pattern size of 2.5 μm or less, which is much smaller than that of a color filter used in LCDs.
As the pattern size becomes smaller, the area of a non-exposed portion of the colored pattern that contacts an alkali developer becomes small, which tends to generate development residue due to poor dissolution.
In addition, as the pattern size becomes smaller, the thickness of the coloring pattern is reduced. In a colored pattern having reduced thickness, the content of a colorant needs to be increased in order to maintain spectroscopic characteristics to a level equal to that of a colored pattern having a thickness that is not reduced. However, if the content of the colorant is increased, generation of development residue may be more pronounced.
In particular, in the case of a green pattern that is often formed in a checkered pattern (hereinafter, referred to as a Bayer pattern), it is difficult to conduct development of a non-exposed part portion of the green pattern as compared with an island pattern of red or blue, thereby increasing the generation of development residue.
In view of the aforementioned circumstances, an object of the invention is to provide a green curable composition for a solid-state image sensor, which can be used to form a green fine pattern having excellent spectroscopic characteristics with a reduced amount of development residue generated at the formation of the fine pattern.
Another object of the invention is to provide a color filter for a solid-state image sensor having excellent spectroscopic characteristics and fineness, and a method of producing the color filter for a solid-state image sensor at high productivity.